Zeachem’s C2 platform uses an acetogenic organism to ferment sugars to acetic acid, which is converted to ethanol. Source: Zeachem. Click to enlarge.

ZeaChem Inc. has produced commercial-grade cellulosic chemicals and ethanol at its 250,000 gallons per year (GPY) demonstration biorefinery in Boardman, Ore. The demonstration facility is intended to showcase the scalability of ZeaChem’s biorefining process and serve as a stepping-stone toward large-scale commercial production.

Similar to a petrochemical refinery that makes multiple fuels and chemicals, ZeaChem’s demonstration facility is employing its C2 (two-carbon) platform to produce cellulose-based ethanol and intermediate chemicals such as acetic acid and ethyl acetate. (Earlier post.) The commercial market potential for all C2 products is $485 billion.

Zeachem’s C3 platform uses a different organism to produce propionic acid, which is then converted to ethyl propionate. The platform uses the same industrial fermentation and recovery process as the C2 platform. Click to enlarge.

Zeachem uses an acetogen to ferment sugars from biomass to acetic acid. Acetogens have several advantages to yeast: they convert all xylose (C5) and glucose (C6) sugars and tolerate all breakdown products of biomass; they operate in harsh environments; and they produce no CO2 as a by-product. (Traditional yeast fermentation creates one molecule of CO2 for every molecule of ethanol. Thus the carbon efficiency of the ZeaChem fermentation process is nearly 100% vs. 67% for yeast.)

The acetic acid is then converted to an ester which is then hydrogenated to make ethanol. To get the hydrogen necessary to convert the ester to ethanol, ZeaChem takes the lignin residue from the fractionation process and gasifies it to create a hydrogen-rich syngas stream. The hydrogen is separated from the syngas and used for ester hydrogenation and the remainder of the syngas is burned to create steam and power for the process.

The C2 and C3 platforms serve a collection of markets. Click to enlarge.

ZeaChem, using a different organism but the same industrial fermentation and recovery process can also create C3 chemicals (three-carbon structure) including propionic acid, ethyl propionate, propanol and propylene. The C3 platform is in the development phase.Together, ZeaChem’s C2 and C3 products address a collection of end markets of more $1 trillion.

As a supplier of competitively-priced products with significant environmental benefits, ZeaChem has formed strategic partnerships with companies that include GreenWood Resources, Valero and Chrysler.

Development of ZeaChem’s first commercial biorefinery is currently underway. Backed by a conditional loan guarantee from the US Department of Agriculture (USDA), the facility will have capacity to produce 25 million GPY or more of ethanol and chemicals from woody biomass and agricultural residues. It will be located at the Port of Morrow in Boardman, Ore., adjacent to ZeaChem’s 250,000 GPY integrated demonstration biorefinery.